Phonograph reproducing apparatus



June 1, 1943.

o. T. MCILVAINE 2,320,879

PHONOGRAPH REPRODUC ING APPARATUS Filed Oct. 15, 1940 Patented June 1,1943 UNITED STATES PATENT orri'c PHONOGBAPH REPRODUCING APPARATUS OranT. Mcllvaine, St. Charles, Ill.

Application October 15, 1940, Serial No. 361,319

6 (Haims.

This invention'relates to an improvement in phonograph reproducingapparatus.

Heretofore, apparatus used to reproduce vibrations that have beenrecorded on a tablet or other record surface, have been usually eithermagnetic or crystal. The crystal reproducers are materially better thanthe magnetic type, and are more frequently used. However, such crystalreproducers have several objections, particularly a typical crystalwhine on high notes, and are susceptible to needle scratch.

The object of this invention is to improve the reproducing qualities,obtaining much better fidelity, and substantially eliminating needlescratch without sacrificing any of the musical range. At the same time,the vibrating mechanism may be constructed very light in weight withgreater high frequency response and less wear on the record, increasingthe life of the latter very materially.

This object is accomplished by controlling the operation of thereproducing apparatus from a light sensitive cell, such as aphoto-electric cell and controlling the light thereto directly by meansof the needle operating from the record, moving laterally in response tothe vibrations recorded thereon.

The accompanying drawing illustrates diiierent embodiments of theinvention, in which:

Figs. 1 to 5 are diagrammatic views showing needle controlled lightvalves associated with lamps.

The invention is shown in difierent embodiments in Figs. 1 to 5, inwhich the sound record needle or stylusis adapted to engage a soundrecord groove in the usual way, and has an extended portion thereofprojecting into a lamp. The needle is mounted for freedom of movementrelative to the lamp, thereby moving the extended portion and the lightcontrolling means connected therewith. In some forms, the extendedportion constitutes one of the leads of the filament thereof, in whichevent it may be constructed of suitable hard conducting metal, such astungsten.

In Fig. l, the lamp l5 has a filament l6 therein with one side thereofconnected directly to an end of the needle ll, th latter extendingmovably through a side wall of the lamp. Vibration of the needle llcontrols the path of light through a slot l8 to a photo-electric cell l9since the filament will be vibrated by the needle and will thereby causea variation of the light on the cell.

Fig. 2 is similar to Fig. 1, except that the filament is arranged toproject a beam of light through the end of the lamp.

In Fig. 3, the needle 2! is connected with a slotted light shutter 22which is movably mounted in the lamp 23, so that vibrations from theneedle 2| will move the shutter sufliciently to vary the light on thecell, while the filament in the lamp 23 remains-stationary.

In Fig. 4, the lamp 25 has a stationary filament 26 therein, while theneedle 21 has a slot 28 formed directly therein to vary the positionthereof in response to vibration of the needle.

Fig. 5 shows another form of lamp 39 having a filament 3! connecteddirectly with the needle 32, while the latter extends through a metaldiaphragm 38 of Kovar or other metal that will seal to the glass orother material and through the center of which the needle extends.

By thus utilizing th reproducing needle that moves in response to therecorded vibrations, the reproduction from the phonograph record may beobtained with very improved results, greater fidelity, lightness inweight with much less wear on the record greatly lengthening its periodof use and also eliminating needle scratch without sacrificing differentfrequencies or tones.

I claim:

1. In a pick-up device adapted to be associated with a light responsivedevice, a stylus adapted to be actuated by a sound record and having anextended portion, an enclosed lamp receiving said extended portion ofthe stylus therein, said extended portion of the stylus having meansconnected therewith in the lamp for varying the light on the lightresponsive device.

2. In a pick-up device adapted to be associated with a light responsivedevice, a stylus adapted to be actuated by a sound record and having anextended portion, an enclosed lamp receiving said extended portion ofthe stylus therein, said extended portion of the stylus having afilament connected therewith and movable by the stylus for varying thelight on the light responsive device.

3. In a pick-up device adapted to be associated with a light responsivedevice, a stylus adapted to be actuated by a sound record and having anextended portion, an enclosed lamp receiving said extended portion ofthe stylus therein, said extended portion of the stylus having afilament connected therewith and movable by the stylus for varying thelight on the light responsive device, and a lead connected with saidstylus for supplying current therethrough to said filament.

4. In a pick-up device adapted to be associated with a light responsivedevice, a stylus adapted to be actuated by a sound record and having anextended portion, an enclosed lamp including an envelope and a lightsource therein, said envelope receiving said extended portion oi thestylus therein, and means actuated by the extended portion of the stylusin the envelope for varying the light on the light responsive device.

5. In a pick-up device adapted to be associated with a light responsivedevice, a stylus adapted to be actuated by a sound record and having anextended portion, an enclosed lamp receiving said extended portion ofthe stylus therein, means mounting said stylus and extended portion formovement relative to said lamp, said lamp including a filament thereinhaving one end thereof connected directly with said extended portion ofthe stylus for varying the light on the light responsive device inresponse to movement 01' the stylus,

6. In a pick-up device adapted to be associated with a light responsivedevice, a stylus adapted to be actuated by a sound record and having anextended portion, an enclosed lamp receiving said extended portion ofthe stylus therein, means mounting said stylus and extended portion formovement relative to said lamp, said lamp including a filament mountedtherein, and means connected with said extended portion of the stylusand having an opening therein for the passage of light from the filamentto the light responsive device and for varying the light thereto inresponse to movement of the stylus.

ORAN T. MCILVAINE.

